Fluid operated swab



Dec. 15, 1931. H. w. FLETCHER V FLUID OPERATED SWAB Filed Nov. 12, 1928 [AVENTOR ATTORNEY BY Jud? -The swab is adapte Patented Dec. 15, 1931 UNITED STATES PATENT OFFICE HAROLD W. FLETCHER, OF HOUSTON, TEXAS, ASSIGNOB TO HUGHES TOOL COMPANY,

' OF HOUSTON, TEXAS, A CORPORATION OF TEXAS FLUID OPERATED SWAB Application filed November 12, 1928. Serial No. 318,777.

My invention relates to swabs such as are employed in raisin liquid from deep wells. to operate through fluid pressure, the length of its stroke being from below the fluid level to the top of the well. The object of the invention is to provide means to automatically regulate the inlet of pressure fluid to the eduction tube through the dropping of the swab to the lower end of its stroke.

It is desired to provide a stop member for the swab to limit its downward movement, and to so mount the said stop member that it may control the inlet openings to the eduction tube.

It is a further object to provide a lower stop member for the plunger which will be adapted to be depressed through fluid pressure while the swab is making its discharge stroke and thus allow the contlnued entrance of pressure fluid during said stroke.

The further objects of my invention will more clearly appear from the specification which follows. In the drawings, Fig. 1 is a broken vertical section of a well tube and easing with my invention installed therein.

Fig. 2 is a transverse section on the plane 22 of Fig. 1, and looking in the direction of the arrow.

Fig. 3 is a vertical section through a well equipment in which my invention is employed, the device being shown somewhat diagrammatically.

The swab is adapted to operate in a tubing 1 which may be termed the eduction tube.

The tube is closed at the upper end except for a lateral outlet 2 spaced below the extreme upper end. The tube extends into the water in the well for any desired depth.

The eduction tube extends through the upper end of the casing 4 which fits about the tube to make a close seal therewith. An inlet 5 for the air is provided, whereby air or gas under pressure can be forced into thge annular space 6 between the casing and tu The swab is shown at 7 in Fig. 1. It is slidable in the tube between a stop member 8 and the upper end of said tube.

The swab has a valve therein adapted to remain open on the falling of the plunger and to be closed by the contact of the valve stem 9 with a pin 10 on the stop member.

The stop member constitutes the main feature of novelty in the invention. It includes a hollow body having cylindrical outer walls 11 which have a close sliding fit within a lower chamber 12 in the eduction tube. The lower end of the body is closed by an upwardly opening valve 13 fitting within a seat 14 formed in a flange 15 at said lower end. The valve has a stem 16 slidable within a guide 17 centrally of a spider 18, as seen in Fig. 2. The upper end of the stop member has a central stop pin 10 extending axially upward to contact with the valve stem 9 as previously set out.

The body of the stop member is resiliently mounted upon a spring 19 supported upon a flange 20 on the tube and tending to hold the stop member upwardly against a flange 22 at the upper end of the chamber 12.

The walls of the chamber have air inlet openings 23 therein near the upper end thereof and said openingsare normally closed by the said sto member. Above the chamber 12 are a num r of small openings 24 which allow a limited amount of air to enter the tube when the liquid level is depressed, as will be later noted.

In operation, the device is submerged in the liquid in the well a suitable distance so that the desired load of liquid will rise above the swab seat. The swab is dropped to its seat after the air pressure has been turned on. The contact of the valve stem 9 with the stop pin 10 will close the plunger valve and force the stop member down sufiiciently to expose the openings 23 allowing the air to enter below the plunger and above the stop member. The air pressure will hold the valve 13 seated and will prevent the stop member from rising so that the air may continue to enter above-the stop member as long as the air pressure is maintained sutiicientlystrong to do so. The pressure fluid will lift the swab and its load to the top where the liquid will be discharged through the outlet 2. When the liquid is fully dischar ed the piston will pass the opening 2 and a low the air will drop to its seat.

pressure to exhaust also. The valve in the plunger will then be opened and the plunger As the air pressure is relieved in the eduction tube, the action of spring 1.9 and the well pressure will force the stop member upwardly to close the inlet openings while the liquid is surging upwardly past the valve 13 and to the desired level above the swab. The air pressure in the annular space 6 will gradually build up forcing the liquid level down in said annular space. The air will bubble in through the small openings 24 and aerate the liquid in the tube sufliciently to cushion the shock of the falling plunger. By the time the plunger strikes the stop member, the liquid level in chamber 6 will be below the inlet openings 23 and the operation will be repeated.

It will be seen that my stop member serves a double function; to close the plunger valve and support said plunger, and also to'shut out the entrance of the air until the plunger is back in place with its load of liquid above it.

The device may thus operate automatically when the entrance of pressure fluid has been regulated to a predetermined volume per unit of time. This volume will have to be determined by the size of the pipes; the time it takes the plunger to fall and the fluid level in the well, but this can be accurately calculated.

Having thus described my invention, what I claim as new is:

1. In a well swabbing device, a casing and an eduction tube therein, said tube extending below the liquid level and having air inlet openings therein, a plunger in said tube, and resilient means to cushion the downward movement of said plunger, and to close said tube against downward passage of fluid below said opening and acting also to normally close said openings during the downward stroke of said plunger.

2. In a well swabbing device, an eduction tube having air inlet openings therein below the liquid level, a plunger in said tube, a stop member in said tube, means to hold said stop member in position to close said openings, a valve in said stop member, said valve being closed and said member being depressed by fluid from said openings when said plunger has reached the lower end of the stroke.

3. In a liquid-lifting device, an eduction tube having lateral air inlet openings below the normal liquid level, a plunger in said tube, and means normally closing said openings, but responsive to the contact of said plunger to expose said openings, there being small air inlets above said means to aerate the liquid in said tube for the purpose described.

4. In a well swabbing device a casing and an eduction tube therein extending from the surface to below the liquid level in the well, said tube having inlet openings therein near the lower end for pressure fluid, a stop member filling the said tube adjacent said openings, means to support said member in position to close said openings on all sides of said tube, means on said stop member axially of said tube to engage a swab plunger and cushion the shock thereof, said plunger acting to move said stop member bodily downward to expose said openings.

5. In a well swabbing device a casing and an eduction tube therein extending from the surface to below the liquid level in the well, said tube having inlet openings therein near the lower end for pressure fluid, a stop member filling the said tube adjacent said openings, means to support said member in position to close said openings on all sides of said tube, means on said stop member to engage and cushion the fall of a swab, a valve in said member, said stop member being responsive to the Weight of said swab to move downwardly and expose said openings, said valve being closed when said openings are exposed, so as to prevent downward movement of said pressure fluid.

6. In a liquid lifting device, an eduction tube having air inlet openings therein below the normal liquid level, a plunger in said tube, a stop member blocking the passage of fluid downwardly in said tube and means to hold said stop member in position to close said openings and said stop member being movable downwardly to allow passage upwardly of pressure fiuid below said plunger.

7. In a pneumatic swab, an eduction tube, an outer concentric pipe for pressure fluid, a foot valve in said tube, a plunger above said foot valve, and a support on said foot valve for said plunger.

8. In a pneumatic swab, an eduction tube, a foot valve in said tube, a plunger above said foot valve, a valve in said plunger means to introduce pressure fluid below said plunger, and a support on said foot valve for said plunger, said foot valve being bodily movable to control the entrance of pressure fluid.

9. In a pneumatic swab, an eduction tube, a foot valve in said tube, a plunger above said foot valve, a valve in said plunger, means to introduce pressure fluid below said plunger, and a support on said foot valve for said plunger, said support acting to close the valve in said plunger.

In testimony whereof I hereunto afiix my signature this 9th day of November A. D.

HAROLD W. FLETCHER. 

